Mtn coverage

Mtn cannot provide a service. If you want to cancel your contract they charge penalties. So im getting punished for the lack of their service. Im using my phone for buisness purposess when eskom goes off im unable to use my phone while Vodacom has perfect useage while load shedding. If got a dual sim phone if have a Vodacom sim as the second simcard and it seems mtn blocks the Vodacom calls because i think the phone is network blocked. I cannot afford canselation penalties and im losing buisness as people cant get a hold of me.